ROLLING BEARING ASSEMBLY
A rolling bearing assembly includes an inner ring and an outer ring, and a plurality of rolling elements interposed between the inner ring and the outer ring. A sealing device having a base end fixed to the inner ring and also having a tip end held in contact with the outer ring to thereby seal a bearing space delimited between the inner ring and the outer ring is provided in the bearing assembly. The sealing device referred to above has a portion thereof that is in the form of a foreign matter intrusion preventing member made of a material capable of permitting lubricating oil to pass therethrough, but preventing an intrusion of a solid foreign matter.
This application is based on and claims Convention priority to Japanese patent application No. 2010-129693, filed Jun. 7, 2010 in Japan, the entire disclosure of which is herein incorporated by reference as a part of this application.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to a rolling bearing assembly and, more specifically, to a rolling bearing assembly of an oil lubricated type that is largely employed in, for example, construction machines and equipments and general industrial machines and equipments.
2. Description of Related Art
A bearing assembly that is employed in, for example, some of travelling sprockets, employed in construction machines and equipments, and some of wheel supports and transmissions employed in, for example, dump trucks having a high overall body weight, does not make use of any sealing member but is used under an oil lubricated system and is operated smoothly when oil being circulated within a confined space is supplied to the bearing assembly.
PRIOR ART LITERATURE
- [Patent Document 1] Japanese Patent No. 4348955
- [Patent Document 2] JP Laid-open Patent Publication No. 2010-19296
In the event that in any of the travelling sprockets, wheels and transmissions a mechanism or the like is employed which accompanies a frictional wear of one or more gears employed in a reduction gear units, intrusion of the circulated oil, admixed with frictionally ground particles, into the bearing assembly may lead to troubles in function of the bearing assembly. In this respect, see the patent documents 1 and 2 listed above. Once this happens, there is the risk that the service life of the bearing assembly will become short.
SUMMARY OF THE INVENTIONIn view of the foregoing, an object of the present invention is therefore to provide a rolling bearing assembly of a type capable of maintaining the functionality as a bearing assembly, for which an undesirable intrusion of foreign matter such as, for example, frictionally ground particles, that is admixed in lubricating oil, into the bearing assembly is prevented to allow only clean oil to be supplied into the bearing assembly as the lubricating oil.
The rolling bearing assembly according to a first aspect of the present invention is a rolling bearing assembly including an inner ring, an outer ring, and a plurality of rolling elements interposed between the inner and outer rings, in which a sealing device having a base end (or first end) fixed to one of the inner and outer rings and also having a tip end (or second end opposite to the first end) held in contact with the other of the inner and outer rings to thereby seal a bearing space delimited between the inner and outer rings. The sealing device referred to above has at least a portion thereof that is in the form of a foreign matter intrusion preventing member made of a material capable of permitting lubricating oil to pass therethrough, but preventing an intrusion of a solid foreign matter.
According to this aspect, since the use has been made of the sealing device, an undesirable intrusion of the foreign matter into the inside of the bearing assembly can be avoided. With the sealing device so utilized, the foreign matter intrusion preventing member forming a part thereof serves to permit the lubricating oil to pass therethrough, but to inhibit the intrusion of the solid foreign matter. Accordingly, only the clean oil having no foreign matter or the like contained therein can be supplied into the inside of the bearing assembly as the lubricating oil, thus allowing the bearing assembly to maintain its functionality as a bearing. Therefore, exfoliation of the raceway surfaces and that of a rolling contact surface, both resulting from the intrusion of the foreign matter, are prevented beforehand, thus making it possible to avoid the possibility that the servicing life of the bearing assembly may undesirably become short. Also, since a foreign matter intrusion preventing function as the foreign matter intrusion preventing member is set up in a portion of the sealing device of the bearing assembly, the device in its entirety can be downsized and the structure thereof can be simplified as compared with, for example, the use of a foreign matter intrusion preventing device separate from the bearing assembly. Accordingly, the versatility of the bearing assembly to the construction machines and equipments and the general industrial machines and equipments can be enhanced.
The foreign matter intrusion preventing member referred to above may be made of a material selected from the group consisting of a non-woven fabric and a porous resin material. According to the non-woven fabric or the porous resin material, by suitably selecting a proper material, such a property as to permit the oil to pass therethrough, but to inhibit the passage therethrough of the solid foreign matter of a size larger than a hole or gap, through which the oil can pass, can be obtained and, by configuring the sealing structure so as to take advantage of such property, only clean oil can be supplied into the inside of the bearing assembly for lubrication of the latter.
The sealing device referred to above may include a sealing plate member fixed to such one of the inner and outer rings, in which case the foreign matter intrusion preventing member is provided in a radial tip end portion of the sealing plate member and is held in contact with the other of the inner and outer rings. In this case, the sealing plate member is fixed to the inner ring or the outer ring, and the foreign matter intrusion preventing member provided at the radial tip end portion of this sealing plate member is held in contact with a portion of the bearing ring confronting therewith. By so constructing the sealing device, only the clean oil can be supplied into the inside of the bearing assembly and be used for lubrication. Since the foreign matter intrusion preventing member is provided at the radial tip end portion of the sealing plate member, the structure of the sealing device can be simplified.
Alternatively, the sealing device referred to above may include a sealing plate member fixed to such one of the inner and outer rings and an elastic sealing member provided in a radial tip end portion of the sealing plate member, in which case the foreign matter intrusion preventing member is provided in a tip end portion of the elastic sealing member; the elastic sealing member has a cutout defined at a plurality of circumferential areas of the tip end portion thereof and covered by the respective foreign matter intrusion preventing member; and a tip end of a portion of the foreign matter intrusion preventing member, where the cutout is defined, and a tip end of a portion of the elastic sealing member, where no cutout is defined, are held in contact with such other of the inner and outer rings. In this case, the foreign matter intrusion preventing member forming a part of the sealing device serves to avoid an undesirable intrusion of the solid foreign matter, but to allow the lubricating oil to pass therethrough into the inside of the bearing assembly. Since the tip end of the portion of the elastic sealing member included in the sealing device, where no cutout is defined, is held in contact with the bearing ring, an effect of preventing the intrusion of the foreign matter can be enhanced as compared with a sealing device employing no elastic sealing member.
The sealing device referred to above may include a sealing plate member fixed to such one of the inner and outer rings and having an aperture extending from inside to outside, and vice versa, of the bearing assembly; and a sealing lip provided in the radial tip end portion of the sealing plate member and held in contact with such other of the inner and outer rings; in which case the foreign matter intrusion preventing member is set up in the aperture formed in the sealing plate member. In this case, with the use of, for example, a mesh-like member as the foreign matter intrusion preventing member, it is possible to allow the lubricating oil to pass therethrough into the inside of the bearing assembly, but to inhibit the intrusion of the solid foreign matter therethrough. The foreign matter or the like tending to intrude through between the tip end of the sealing device and the bearing ring is intercepted by the sealing lip.
The rolling bearing assembly referred to above may be a tapered roller bearing assembly of which inner rings has a collar at both ends thereof, in which case the sealing plate member is fixed having been mounted on an outer diametric surface of a large diameter end collar of the inner ring. In this case, the sealing device can be easily fixed to the inner ring and the number of assembling steps can be reduced accordingly. An inner peripheral surface of the inner ring may be provided with an escape recess that is indented in a direction towards an outer diametric side, in which case the sealing plate member is fixedly inserted into this escape recess. In this case, the sealing device can be retained by the rolling bearing assembly alone and the handling during the assemblage of the rolling bearing assembly can be eased. By way of example, there is no need for a user, who is desirous of using the bearing assembly, to incorporate the sealing device and, therefore, the number of assembling steps can be reduced.
The outer ring referred to above may have a raceway surface extension formed by extending an outer ring raceway surface in an outer ring widthwise direction, in which case the tip end of the sealing device is held in contact with the raceway surface extension. The outer ring may have a raceway surface extension formed by extending an outer ring raceway surface in an outer ring widthwise direction, in which case alternatively the sealing lip may be held in contact with the raceway surface extension. In those cased, with the tip end of the sealing device or the sealing lip of the sealing device caused to contact the raceway surface extension in the radial direction, only the clean oil having no foreign matter or the like contained therein can be supplied into the inside of the bearing assembly as the lubricating oil.
The rolling bearing assembly according to a second aspect of the present invention includes an inner ring and an outer ring, and a plurality of rolling elements interposed between the inner and outer rings; and a sealing device having a base end fixed to one of the inner and outer rings and also having a tip end held in contact with the other of the inner and outer rings to thereby seal a bearing space delimited between the inner and outer rings, in which case the sealing device includes a sealing plate member, fixed to such one of the inner and outer rings, and a lip-like elastic sealing member provided in a radial tip end portion of the sealing plate member to define a minute gap between the lip-like elastic sealing member and such other of the inner and outer rings for permitting lubricating oil to pass therethrough, but preventing an intrusion of a solid foreign matter.
According to this second aspect, the lip-like elastic sealing member in the sealing device serves to allow the lubricating oil to pass through the minute gap delimited between it and the bearing ring, but to inhibit the passage of the foreign matter therethrough into the inside of the bearing assembly. As the elastic sealing member, a rubber of a kind having a weak force of straining a lip, for example, is utilized. A rubber or resinous material of a kind capable of exerting a pressing force of such a magnitude that when the tip end portion of the lip is held in contact with the bearing ring, a tip end of the lip can undergo an undulate motion enough to form the minute gap at a plurality of sites between it and the bearing ring is utilized. In other words, this minute gap serves to pass the oil therethrough, but to inhibit the passage therethrough of the foreign matter of a kind larger than the minute gap. Accordingly, only the clean oil having no foreign matter or the like contained therein can be supplied into the inside of the bearing assembly as the lubricating oil, allowing the functionality as the bearing assembly to be maintained. Accordingly, exfoliation of raceway surfaces and that of a rolling contact surface, both resulting from the intrusion of the foreign matter, can be prevented beforehand, thus making it possible to avoid the possibility that the servicing life of the bearing assembly may undesirably become short.
A magnetized member for adsorbing frictionally ground particles of a magnetic material, which is the foreign matter contained in the lubricating oil, may be provided in a portion of the sealing device. In this case, by the effect of a magnetic force exerted by the magnetized member, the frictionally ground particles are forcibly removed from the lubricating oil containing the frictionally ground particles. Accordingly, only the clean oil having no foreign matter or the like contained therein can be supplied into the inside of the bearing assembly.
Any combination of at least two constructions, disclosed in the appended claims and/or the specification and/or the accompanying drawings should be construed as included within the scope of the present invention. In particular, any combination of two or more of the appended claims should be equally construed as included within the scope of the present invention.
In any event, the present invention will become more clearly understood from the following description of preferred embodiments thereof, when taken in conjunction with the accompanying drawings. However, the embodiments and the drawings are given only for the purpose of illustration and explanation, and are not to be taken as limiting the scope of the present invention in any way whatsoever, which scope is to be determined by the appended claims. In the accompanying drawings, like reference numerals are used to denote like parts throughout the several views, and:
A first preferred embodiment of the present invention will be described in detail with particular reference to
The details of the sealing device 5 will now be discussed. As best shown in
In the instance now under discussion, the material for the foreign matter intrusion preventing member 8 is employed in the form of a non-woven fabric. When a sealing structure is so designed as to take advantage of a property of the non-woven fabric, that is, a property of permitting the oil to pass therethrough, but inhibiting the passage therethrough of a solid foreign matter of a kind having a particle size greater than the dimensions of a clearance through which the oil can pass, only clean oil is supplied through the foreign matter intrusion preventing member 8 into the inside of the bearing assembly and used for lubrication. It is to be noted that since the mounting portion 9 of the sealing plate member 7 is firmly mounted on the outer diametric surface 6a of the large diameter end collar 6 of the inner ring 1 under interference fit, a possible intrusion of the foreign matter and the oil through a contact area between the outer diametric surface 6a of the large diameter end collar 6 and the mounting portion 9 is assuredly blocked off.
According to the rolling bearing assembly of the structure hereinabove described, the foreign matter intrusion preventing member 8 of the sealing device 5 allows the lubricating oil therethrough into the inside of the bearing assembly, but prevents the slid foreign matter from intruding into the inside of the bearing assembly. Accordingly, only the clean oil free from the foreign matter or the like, that is, the clean oil that does not contain the foreign matter or the like mixed therein is supplied into the inside of the bearing assembly as the lubricating oil, thus maintaining a functionality as the bearing assembly. Accordingly, exfoliation of the raceway surfaces 1a and 2a and that of a rolling contact surface, both resulting from the intrusion of the foreign matter, are prevented beforehand, thus making it possible to avoid the possibility that the servicing life of the bearing assembly may undesirably become short. Also, since a foreign matter intrusion preventing function is set up with a portion of the sealing device 5 of the bearing assembly constituted by the foreign matter intrusion preventing member 8, the device in its entirety can be downsized and the structure thereof can be simplified as compared with, for example, the use of a foreign matter intrusion preventing device separate from the bearing assembly. Accordingly, the versatility of the bearing assembly to the construction machines and equipments and the general industrial machines and equipments can be enhanced.
Since the foregoing rolling bearing assembly is a tapered roller bearing assembly of a type utilizing the inner ring 1 having a collar at both ends thereof and since the mounting portion 9 of the sealing plate member 7 is fixedly mounted on the outer diametric surface 6a of the large diameter end collar 6 of the inner ring 1, the sealing device 5 can be simply fixed to the inner ring 1 and the number of assembling steps can be reduced. Also, since the base end of the foreign matter intrusion preventing member 8 is sandwiched in between the two steel plates 7a and 7b in the cylindrical wall portion 11 which defines the radial tip end portion of the sealing plate member 7 and the foreign matter intrusion preventing member 8 is removably provided on the cylindrical wall portion 11, only the foreign matter intrusion preventing member 8 can be easily replaced at the time of, for example, maintenance of the bearing assembly. It is nevertheless possible to replace the sealing device 5 in its entirety.
Hereinafter, second to thirteenth preferred embodiments of the present invention will be discussed in detail. It is, however, to be noted that in the description that follows, component parts, which are referred to in describing one of the preferred embodiments, but which are similar to or corresponding to those referred to in any of the remaining preferred embodiments, are designated by like reference numerals and the details thereof are not reiterated for the sake of brevity. Where in describing one of the preferred embodiments, only a portion of the construction is referred to, other portions of such construction are to be understood as similar to those referred to in the previously described preferred embodiment or embodiments. Not only can component parts, which are specifically referred to in describing each of the preferred embodiments, be combined, but also parts of the preferred embodiments can be combined unless such combination pose any problem.
The rolling bearing assembly designed in accordance with the second preferred embodiment shown in
Even in the second embodiment of the present invention described above, the foreign matter intrusion preventing member 8 of the sealing device 5A serves to allow the lubricating oil to pass therethrough into the inside of the bearing assembly, but to prevent the solid foreign matter from intruding thereinto.
Accordingly, only the clean oil free from the foreign matter or the like is supplied as the lubricating oil into the inside of the bearing assembly, thus maintaining the functionality as the bearing assembly. Other functions and effects are similar to those afforded by the rolling bearing assembly shown in and described with particular reference to
According to the third preferred embodiment of the present invention shown in
According to the third embodiment of the present invention described above, since a portion of the sealing plate member 7 is fixedly sandwiched in between the end face 1b of the inner ring 1 on the large diameter end side and the counterpart member 12, a widthwise acting force works between the counterpart member and the inner ring end face 1b by means of, for example, a preload of the bearing assembly. Accordingly, the radial lower half portion 7aa of the steel plate 7a, forming a part of the upright wall portion 10 on the outer side, is urged towards the inner ring end face 1b with the sealing device 5B firmly fixed consequently. Therefore, an undesired separation of the sealing device 5B from the bearing assembly under the influence of vibrations or the like can be avoided. Also, because of the use of the foreign matter intrusion preventing member 8 of the sealing device 5B, only the clean oil free from the foreign matter or the like can be supplied into the inside of the bearing assembly as the lubricating oil. It is to be noted that the counterpart member 12 for sandwiching a portion of the sealing plate member 7 may not be limited to the inner ring spacer as described above, but any other member such as, for example, a shaft or a flange may be used for the counterpart member 12.
According to the fourth preferred embodiment of the present invention shown in
In the fifth preferred embodiment of the present invention shown in
The rolling bearing assembly designed in accordance with the sixth preferred embodiment of the present invention shown in
In the seventh preferred embodiment of the present invention shown in
The sealing device 5F, designed in accordance with the eighth preferred embodiment of the present invention shown in
In the ninth preferred embodiment of the present invention shown in
In this case, the foreign matter intrusion preventing member 8 serves to permit the lubricating oil to pass therethrough, but to avoid an undesirable intrusion of the solid foreign matter therethrough. Since the elastic sealing member 19 is such that the tip end 19b, where no cutout 19a is formed, is held in contact with the outer ring end face 2b, an effect of avoiding the undesirable intrusion of the foreign matter can be highly enhanced as compared with that afforded by the sealing device of a type having no elastic sealing member employed. It is to be noted that although in this tenth embodiment of the present invention described above, the cutout 19a in the elastic sealing member 19 has been shown and described as covered by the respective foreign matter intrusion preventing member 8, the present invention is not necessarily be limited to such structure. For example, such a structure may be employed in which the elastic sealing member 19 may be made up of, for example, two annular rubber plates or two annular resin plates with an annular or rectangular shaped foreign matter intrusion preventing member(s) 8 fixedly sandwiched between two rubber plates.
The rolling bearing assembly shown in
Referring now to
In the practice of any one of the foregoing embodiments of the present invention, the non-woven fabric, if used therein as a material for the foreign matter intrusion preventing member 8, may be replaced with a porous resin material, or the porous resin material, if alternatively used therein as a material for the foreign matter intrusion preventing member 8, may be replaced with a non-woven fabric. Particularly, although in describing the embodiment shown in
Also, although in describing any one of the foregoing embodiments of the present invention, the sealing plate member 7 has been shown and described as fixed to the inner ring 1 with the foreign matter intrusion preventing member 8 or the elastic sealing member 20 held in contact with the outer ring 2, the structure may be employed in which the sealing plate member 7 is conversely fixed to the outer ring 2 with the foreign matter intrusion preventing member 8 or the elastic sealing member 20 held in contact with the inner ring 1 (for example, the inner ring outer peripheral surface or the inner ring end face).
In addition, in the practice of any one of the foregoing embodiments except for the embodiment shown in and described with reference to
Although the rolling bearing assembly adopted in the practice of any one of the foregoing embodiments of the present invention has been shown and described in the form of a single row tapered roller bearing assembly, it may be of a dual row type.
Yet, any one of the sealing devices shown and described hereinbefore may be applied to a deep groove ball bearing assembly, an angular contact ball bearing assembly, a cylindrical roller bearing assembly or a self-aligning roller bearing assembly.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings which are used only for the purpose of illustration, those skilled in the art will readily conceive numerous changes and modifications within the framework of obviousness upon the reading of the specification herein presented of the present invention. Accordingly, such changes and modifications are, unless they depart from the scope of the present invention as delivered from the claims annexed hereto, to be construed as included therein.
REFERENCE NUMERALS
-
- 1 . . . Inner ring
- 2 . . . Outer ring
- 2a . . . Outer ring raceway surface
- 2aa . . . Raceway surface extension
- 3 . . . Rolling element
- 5 to 5G . . . Sealing device
- 6 . . . Large diameter end collar
- 7 . . . Sealing plate member
- 8 . . . Foreign matter intrusion preventing member
- 13 . . . Escape recess
- 15 . . . Magnetized member
- 17 . . . Sealing lip
- 18 . . . Aperture
- 19 . . . Elastic sealing member
- 19a . . . Cutout
- 20 . . . Elastic sealing member
Claims
1. A rolling bearing assembly which comprises:
- an inner ring and an outer ring, and a plurality of rolling elements interposed between the inner and outer rings;
- a sealing device having a base end fixed to one of the inner and outer rings and also having a tip end held in contact with the other of the inner and outer rings to thereby seal a bearing space delimited between the inner and outer rings; and
- a foreign matter intrusion preventing member made of a material capable of permitting lubricating oil to pass therethrough, but preventing an intrusion of a solid foreign matter, the foreign matter intrusion preventing member being provided in at least a portion of the sealing device.
2. The rolling bearing assembly as claimed in claim 1, in which the foreign matter intrusion preventing member is made of a material selected from the group consisting of a non-woven fabric and a porous resin material.
3. The rolling bearing assembly as claimed in claim 1, in which the sealing device comprises a sealing plate member fixed to such one of the inner and outer rings and the foreign matter intrusion preventing member is provided in a radial tip end portion of the sealing plate member and is held in contact with the other of the inner and outer rings.
4. The rolling bearing assembly as claimed in claim 1, in which the sealing device comprises a sealing plate member fixed to such one of the inner and outer rings and an elastic sealing member provided in a radial tip end portion of the sealing plate member, the foreign matter intrusion preventing member being provided in a tip end portion of the elastic sealing member; in which the elastic sealing member has a cutout defined at a plurality of circumferential areas of the tip end portion thereof and covered by the respective foreign matter intrusion preventing member; and in which a tip end of a portion of the foreign matter intrusion preventing member, where the cutout is defined, and a tip end of a portion of the elastic sealing member, where no cutout is defined, are held in contact with such other of the inner and outer rings.
5. The rolling bearing assembly as claimed in claim 1, in which the sealing device comprises:
- a sealing plate member fixed to such one of the inner and outer rings and having an aperture extending from inside to outside, and vice versa, of the bearing assembly;
- a sealing lip provided in the radial tip end portion of the sealing plate member and held in contact with such other of the inner and outer rings; and
- the foreign matter intrusion preventing member being set up in the aperture formed in the sealing plate member.
6. The rolling bearing assembly as claimed in claim 3, in which the rolling bearing assembly is a tapered roller bearing assembly of which inner rings has a collar at both ends thereof and in which the sealing plate member is fixed having been mounted on an outer diametric surface of a large diameter end collar of the inner ring.
7. The roller bearing assembly as claimed in claim 4, in which the rolling bearing assembly is a tapered roller bearing assembly of which inner rings has a collar at both ends thereof and in which the sealing plate member is fixed having been mounted on an outer diametric surface of a large diameter end collar of the inner ring.
8. The rolling bearing assembly as claimed in claim 3, in which an inner peripheral surface of the inner ring is provided with an escape recess that is indented in a direction towards an outer diametric side and the sealing plate member is fixedly inserted into this escape recess.
9. The rolling bearing assembly as claimed in claim 4, in which an inner peripheral surface of the inner ring is provided with an escape recess that is indented in a direction towards an outer diametric side and the sealing plate member is fixedly inserted into this escape recess.
10. The rolling bearing assembly as claimed in claim 1, in which the outer ring has a raceway surface extension formed by extending an outer ring raceway surface in an outer ring widthwise direction, the tip end of the sealing device being held in contact with the raceway surface extension.
11. The rolling bearing assembly as claimed in claim 5, in which the outer ring has a raceway surface extension formed by extending an outer ring raceway surface in an outer ring widthwise direction, the sealing lip being held in contact with the raceway surface extension.
12. The rolling bearing assembly as claimed in claim 1, further comprising a magnetized member for adsorbing frictionally ground particles of a magnetic material, which is the foreign matter contained in the lubricating oil, is provided in a portion of the sealing device.
13. A rolling bearing assembly which comprises:
- an inner ring and an outer ring, and a plurality of rolling elements interposed between the inner and outer rings; and
- a sealing device having a base end fixed to one of the inner and outer rings and also having a tip end held in contact with the other of the inner and outer rings to thereby seal a bearing space delimited between the inner and outer rings,
- the sealing device comprising a sealing plate member, fixed to such one of the inner and outer rings, and a lip-like elastic sealing member provided in a radial tip end portion of the sealing plate member to define a minute gap between the lip-like elastic sealing member and such other of the inner and outer rings for permitting lubricating oil to pass therethrough, but preventing an intrusion of a solid foreign matter.
14. The rolling bearing assembly as claimed in claim 13, further comprising a magnetized member for adsorbing frictionally ground particles of a magnetic material, which is the foreign matter contained in the lubricating oil, is provided in a portion of the sealing device.
Type: Application
Filed: May 30, 2011
Publication Date: Mar 28, 2013
Inventors: Yasuhiko Shimizu (Kuwana-shi), Fumihiro Murakami (Kuwana-shi)
Application Number: 13/702,450
International Classification: F16C 33/76 (20060101);